Studio Application 1
Keyboardists and guitarists looking for rotary speaker swirl, phase sweeps, and vintage pitch/timbre movement.
Fat Berry DSP / Modulation plug-ins Buying Guide
Movement with somewhere to go.
Modulation plug-ins animate static tracks through phase and amplitude movement. Taser is a phaser voiced after vintage stomp boxes; Tremble is a tremolo voiced after vintage amps and pedals. Both offer stereo movement and tempo sync for guitars, electric pianos, synths and vocals. Taser: A phaser with JFET, OTA and Opto circuits and 4, 6 or 8 stages. Tremble: A tremolo with Bias, Opto and Harmonic circuits, in mono, stereo or pan. Movement can give a held note a pulse or let a simple chord occupy a changing space. Begin with the effect mixed quietly under the source. Adjust its speed while the rhythm plays, then listen for the moments where the motion supports the phrase. A slow sweep can work behind a vocal; stronger pulses may suit a transition. Check the result in mono and leave enough steady sound for the listener to keep following the musical line. Start free with Taser, which is free to keep.
Written & tested by Rory Browne (Founder & DSP Developer) · Last updated:
Compare 2 modulation plug-ins
Use Cases & Fit
Who modulation plug-ins are for — and how to choose
Our ears are wired to notice change. A static pad or held guitar chord quickly recedes into the background, whereas subtle modulation keeps the listener engaged across a four-bar sustain. The key is choosing a modulation topology that moves the texture without destabilising the rhythm or fundamental pitch.
Studio Application 2
Electronic and indie producers animating static synth pads, DI basslines, or background vocal stacks.
Studio Application 3
Mix engineers adding stereo width and gentle evolution to supporting arrangement layers.
At the desk
How do you choose and dial in modulation plug-ins?
Pace the sweep to the musical phrase
A slow 2-to-4-bar phaser or LFO cycle feels like a natural arrangement swell, while a faster rotary tremolo locks into eighth-note or sixteenth-note rhythmic energy.
Keep a stable dry anchor in the low frequencies
Heavy phase or pitch modulation below 150 Hz can make basslines lose weight when summed to mono. Blend the wet/dry mix so the fundamental stays solid.
Always verify stereo modulation in mono
Wide stereo phase offsets create impressive headphone width, but out-of-phase components cancel on mono phone speakers and club systems. Check mono compatibility before finalising depth.
Modulate supporting parts so the lead stays still
When backing pads and rhythm guitars gently move in stereo, an unmodulated centre vocal sounds even more grounded and authoritative.
Signal-chain placement
Place modulation before overdrive/amp stages when you want harmonic distortion to react to the sweep (classic guitar pedal order), or after EQ/compression for polished stereo studio movement.
Side-by-side specifications
Modulation plug-ins comparison table
The specifications below come from the published catalogue and release metadata. All licences are perpetual single-user licences (3 machine activations, 14-day full refund window).
| Plug-in | Price (USD) | Formats | OS Support | Best For / Sonic Role | Walkthrough |
|---|---|---|---|---|---|
| Taser | Free ($0) | VST3, AU | Windows 10 or later, 64-bit (x86-64) · 11.0 | A phaser with JFET, OTA and Opto circuits and 4, 6 or 8 stages. | Audio & specs ↗ |
| Tremble | Free ($0) | VST3, AU | Windows 10 or later, 64-bit (x86-64) · 11.0 | A tremolo with Bias, Opto and Harmonic circuits, in mono, stereo or pan. | Watch demo ↗ |
How we test at -16 LUFS
Listening tests & common mix mistakes to avoid
Primary listening check
Listen through an entire 16-bar section in stereo and then in mono. Keep the modulation setting that adds life and motion without pulling attention away from the lead melody.
Four-step studio audition checklist
- Set depth to 50% and dial in the rate/speed against your song tempo before deciding how intense the effect should be.
- Reduce wet/dry mix until the modulation is felt as motion rather than heard as an obvious seasick pitch wobble.
- Toggle your monitor controller to mono and confirm the mid-frequency body does not hollow out during the sweep trough.
- Automate modulation depth up slightly during instrumental transitions or breakdowns for arrangement lift.
Common mistakes when using modulation plug-ins
- Setting modulation rate to a random speed that fights the song’s rhythmic subdivision.
- Running 100% wet stereo modulation on a primary bass or lead vocal without checking mono phase cancellation.
- Putting different fast modulation effects on multiple tracks until the mix feels rhythmically unfocused.
The tools
Modulation plug-ins, made by Fat Berry.
Each card links to current formats, controls, demos and the live price on its product page.
Modulation
Taser
A phaser with JFET, OTA and Opto circuits and 4, 6 or 8 stages.
Hear and inspect Taser ↗
Modulation
Tremble
A tremolo with Bias, Opto and Harmonic circuits, in mono, stereo or pan.
Hear and inspect Tremble ↗Studio notes
Read it, then hear it.
Frequently Asked Questions
Modulation plug-ins FAQ
Is there a free modulation plug-in in the Fat Berry DSP range?
Yes. Taser and Tremble are free ($0 USD) in the Free Pickings collection. Taurus Chorus is a separate paid chorus at $29.99 USD regular price.
What is Coil and where can I watch its demo?
Coil (/plugins/coil) is a physical spring reverb in the Reverb category, with one to six active paths, damping, Drive and Width. Its video and audio stem walkthrough is at /demos/coil.
Should modulation go before or after delay and reverb?
Putting modulation before delay and reverb animates the source while letting the space decay smoothly. Putting subtle modulation only on the delay or reverb return leaves the dry centre untouched while widening the ambient tail.